In a mechanical type timepiece, there has been developed a mechanism to display of remaining time for which a spring can be operated, that is, to display a duration time period of the timepiece (power reserve mechanism). According to such a power reserve mechanism, there is used a planetary gear mechanism for reciprocating in a fan-like shape a hand for displaying the duration time period of the timepiece.
For example, there is disclosed a constitution of a timepiece with spring winding state display in JP-A-9-21886.
As shown in FIG. 14, such a conventional timepiece with spring winding state display is constituted by a ratchet wheel 1, a planetary reduction wheel gear 7 in mesh with a barrel complete 2, a planetary gear mechanism constituted by a planetary wheel 8 rotatably attached to an eccentric portion of the planetary reduction wheel gear 7, a sun wheel 6 in mesh with a planetary pinion 8b and a second sun wheel 4 in mesh with a planetary gear 8a, a display transmission wheel 17 in mesh with a sun wheel pinion 6c, a display wheel 18 in mesh with a display transmission pinion 17b, a display degree determining pin 9b and a planetary transmission wheel 19 in mesh with the ratchet wheel 1 and a second sun gear 4a.
However, according to the conventional timepiece with spring winding state display, there pose the following problems.
(1) Gears constituting the planetary gear need a large space in view of the characteristic and the speed reduction ratio cannot be increased. For example, the speed reduction ratio is generally about 1/2. Accordingly, a plurality of speed reduction gear trains use other than the planetary gear are required.
(2) Therefore, in order to mount a power reserve mechanism to a timepiece, a large space has to be secured in a movement of the timepiece.
(3) Since an angle of reciprocating a hand for displaying of duration time of the timepiece in a fan-like shape, is determined by the speed reduction ratio of the planetary gear and the speed reduction gear trains related thereto and accordingly, the angle of reciprocating the hand in a fan-like shape is difficult to change.
Hence, in order to resolve the above-described problems, objects of the invention reside in points described below.
(1) To reduce a number of parts constituting a timepiece with spring winding state display.
(2) To downsize a movement of a timepiece with spring winding state display.
(3) To realize a timepiece with spring winding state display in which rotation range of a power reserve hand (a hand operating fan angle) can be easily changed.